Avengers: Doomsday star Robert Downey Jr. has posted artwork showing Doctor Doom as a dad for this year's father's day.

The artwork, shared by Downey Jr. via his Instagram account, features a smiling child holding Doctor Doom's hand, as the pair fly kites together. (The kites have Avengers and Fantastic Four symbols on them that have been crossed out.) A caption reads "I love doom Dad," supposedly written by Doom's child.

While a playful marker of the real-world father's day, the artwork also ties into a popular fan theory for Doctor Doom's backstory in the forthcoming Avengers: Doomsday — and potentially the reason Doom becomes an antagonist in the first place.

Fans have long thought Doom will have a tragic background, where his family will have been inadvertently wiped from existence by the Avengers' previous multiversal shenanigans. Remember, of course, that the events of Avengers: Endgame saw various Infinity Stones taken by the Avengers — something Tilda Swinton's Ancient One warned would have dire consequences on the timelines these stones originated from.

Of course, Steve Rogers promised he would return the Infinity Stones — but what if something went wrong along the way that caused Doom's family to be scrubbed from existence? As a plot device to bring Rogers back into action and see Doom seek revenge (such as on Rogers' own newly-revealed son?), it seems logical. The loss of Doom's own family would also tie in to his fascination with the young Franklin Richards, seen at the end of The Fantastic Four: First Steps.

Marvel has given few hints at the plot of Avengers: Doomsday, though fans are taking this artwork as a hint that Doom did have a child at one point.

For more on Doomsday's story, you may want to read up on the leaked footage that has begun circulating online in recent days — or try and stay unspoiled until the movie arrives in theaters on December 18. In the meantime, Tom Holland has been doing his best to avoid revealing spoilers for upcoming MCU projects, while former Jean Grey actress Famke Janssen has plenty to say about being left out of the new Avengers movies.

Tom Phillips is IGN's News Editor. You can reach Tom at tom_phillips@ign.com or find him on Bluesky @tomphillipseg.bsky.social